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Leaky Sierra Mastercylinder
James - 30/6/05 at 11:00 AM

A small amount of brake fluid is leaking out of the back of my Sierra m/cyl.

Is it junk or a case of fitting a rebuild kit from Brakesint (not something I've done before- difficult?) or something else?

IIRC someone said something about it being possible to turn the seal round if the m/cyl was pumped without fluid?

Thanks,
James

DarrenW - 30/6/05 at 11:07 AM

iirc British trident mentioned the seal reversal thing. He is quite knowledgable so hopefully will join the discussion.

When i was looking at Master cylinders i found out that there are at least two types on Sierras, one of them you cant get seal jits for. I got silly prices quoted for new ones (£80 - 90 mark) but finally go a very sensible price from Mac#1 (around £50 iirc). I would assume it is the Lucas one that you cant get seals for as i ended up having to buy the new lucas cylinder from Mac#1. The mounting holes are different on the different types - this is one of the identifying features.

Does this make any sense???? I hope it starts to help you. sorry, i dont know wht oil would come out of the back of yours but imho if there is any doubt over it then replace it as a matter of course. Its always nice to be able to stop!

britishtrident - 30/6/05 at 11:40 AM

Rear seal on dual circuit cylinders tends to fail because it gets a fair bit of crud, usually fixes easily with clean up and news seals and lots of red rubber grease.


At one time dual circuit cylinder repair kits were hard to get so fixed a couple of Avenger/Sunbeam ones with Cortina Mk3 rear wheel cylinder seals (SP2715 istr) only changing the the rear seals -- they worked fine for at least another 50,000+ miles

[Edited on 30/6/05 by britishtrident]

[Edited on 30/6/05 by britishtrident]

Hellfire - 30/6/05 at 03:28 PM

Funnily enough - our's has just done the very thing. Stripped it down, checked seals and it's amazing how much SH!TE get in there. Checked seals and bores which looked fine. Put it back together - done, no leak.

HTH

Danozeman - 30/6/05 at 03:57 PM

Is it worth doing as another cyl can be got from breakers for not alot of money??

James - 6/7/05 at 09:03 AM

Thanks for the replies guys- why are so many things going wrong now!

I'll try stripping it and cleaning it up.

I've not heard of red rubber grease. Is this something specially for brakes?

Thanks for the advice everyone.

Cheers,
James

JoelP - 6/7/05 at 09:42 AM

a new one should only be a tenner from a scrappy, and you can remove them without getting mucky! thats what i'd do myself, unless you have spare time and fancy taking it apart to clean it. I certainly wouldnt splash out on a rebuild kit though.

britishtrident - 6/7/05 at 03:13 PM

quote:
Originally posted by James
Thanks for the replies guys- why are so many things going wrong now!

I'll try stripping it and cleaning it up.

I've not heard of red rubber grease. Is this something specially for brakes?

Thanks for the advice everyone.

Cheers,
James


Red rubber grease can be quite hard to find it is usually included in Lucas/Girling mastercylinder kits -- some accessory shops sell it from cards "Beta Part" brand falling that LSUK and its agents should be able to supply.

Dingz - 11/7/05 at 09:44 PM

James, if you want brakes replace the seals, they could be 20 plus years old! If it is the 3 outlet girling cylinder the Lucas kit no. is SP7704 and was about £10 last year from my local factors. They are straight forward to change, the hardest bit is fitting the plastic reservoir back on.